Induction cookers have come to be known for their advantageous features such as safety, cleanness, and high heating efficiency, and therefore have been widely used, for example, in domestic and industrial kitchens in recent years.
In some induction cookers, when the user turns on the power switch, a locked state occurs requiring the user to operate an unlock key, which is a touch key for releasing the locked state, and then to operate a heat on key for starting heating (see, for example, Patent Literatures 1 and 2 below).
Such an induction cooker has a dedicated unlock key. When the cooker includes a number of operation keys for the control mode such as a temperature control key, a water heating key, and a rice cooking key in addition to the heating start key, the user is required to perform an unlock operation every time before operating one of these operation keys, making the induction cooker user-unfriendly. Thus, it has been an urgent issue to reduce the number of operation keys so as to simplify the operation while requiring the user to perform a two-step operation before starting heating so as to ensure safety.    Patent Literature 1: Japanese Patent Unexamined Publication No. 2005-265207    Patent Literature 2: Japanese Patent Unexamined Publication No. 2005-265212